Can Surface Treatments Increase Bonding Durability of Eroded Dentin?

Objectives: This in vitro study aimed to evaluate the microtensile bond strength of a universal adhesive (Single Bond Universal – SBU; 3M) on eroded dentin substrates, using different surface treatments, after 24 hours and 6 months of water storage.
Methods: Forty human third molars were sectioned and the dentin specimens were subjected to an erosive-abrasive challenge. Subsequently, specimens were randomly divided into five experimental groups (n=8) and received the following surface treatments: C: control group (no treatment); B: roughening with a diamond bur; A: sandblasting with aluminum oxide; BA: roughening with a diamond bur + sandblasting with aluminum oxide; L: treatment with erbium laser (Er:YAG). After surface treatments, all specimens were restored using a universal adhesive and composite resin (Filtek Z350 XT; 3M). The specimens were sectioned to obtain sticks with a 0.8 mm² cross-sectional area, after 24 hours and after 6 months, and were subjected to microtensile bond strength (µTBS) testing on a universal testing machine at a crosshead speed of 0.5 mm/minute until failure. Data were analyzed using two-way repeated measures ANOVA and Tukey's test (α = 5%).
Results: There was no statistically significant difference between aging conditions, but there was a difference among the surface treatments. No difference was observed between the treatments after 24 hours of storage. However, after 6 months, the L group achieved higher bond strength values and was statistically different from the C group.
Conclusions: Laser surface treatment exhibited stable dentin bonding after 6 months and can be indicated in cases of eroded dentin.